Talk:Mars/@comment-37765878-20181212115630/@comment-37765878-20190223162405
Hi Rob, Sorry, I catched a cold (with fever and everything), so I couldn't answer right away. Still not over yet, but at least I am beginning to think straight again ;) So, thanks for your reply. And there is more to your argument: To remedy the most pressing problem of a weaker gravitational pull, there can be centrifugal plates (or rings) installed in those craters or caverns that make up for the rest of the missing percentage of Earth' 1 gee. The thing is, it's rather complicated, highly maintenance laden and not a system that could easily be scaled up to allow for rapid growth of the population (so there are limiting factors). But it is at least possible. I actually expect that to happen on stations installed on Luna and definitelly with Stanford Toruses in Earth orbit (which are a radically scaled down version of an O'Neill Cylinder - so the Stanford Torus is probably the first semi-megastructure built by us in the coming 100 years or so). The Stanford Torus will also be the only structure of its size, that will be build from materials exported from Earth (which is basicly a ruinous endeavour - even if we intend to make an O'Neill Cylinder out of it). Mass Drivers will make it easy getting raw materials into orbit - from Luna, Mars, Mercury; basicly every celestial body with a gravitational pull that is dramatically lower than 1 gee. So, the first O'Neill Cylinder will be built out of "alien" materials - including the soil crops will grow on in these cylinders. And that's the argument: When it is more easy and safe to create a living space than ever before, all previous plans for similiar efforts should be off the table (I completely disregard the emotional attachment of people to certain objects, like Earth or Mars, so this is a rather pragmatic view at the problem). An O'Neill Cylinder must be properly shielded in order to be viable. So you have the living space, the gravitational pull, the energy, are mobile and have perfect shielding that is not just good enough for protecting you from meteorites, but also from solar flares and even gamma ray bursts (unless the sun would go nova - then we'd be screwed, regardless of shielding ;) ), and after all this, it bears the question: Why terraforming at all? There are no rational reasons to do it, when you can do the Habitat thing. I am sure, mankind will have a host of reasons of why terraforming is preferable over space habitats, but they just can't be effective ones. To provide some thoughts about the future, here is what I believe: Earth and Moon will probably never be disassembled. The attachment as being our home and cradle is just too strong. We will, though, canibalize the Moon as much as it is sustainable without causing detrimental effects on Earth as a result. I am confident that Mercury will be entirely disassembled in the coming 1000 years to build at least a basic Dyson Swarm, to feed our exponentially growing need for free energy (this would allow for mass-transmorph of Matter into Anti-Matter... if we haven't tried it before that, this development will kick open interstellar travel for us, because AMat will allow for speeds up to 90% c and more; it is technically possible to do it today, but only in miniscule amounts - we need a Dyson Swarm to make it efficient). Venus seems to be a problematic colonization target, because the only means with which we could 'colonize' it now, is by utilizing floating cities. I don't know if that is a viable choice to built a society out of at all, because with proper solar shielding, the sulfid and CO2 levels would drop rapidly - which those cities need to stay afloat (so you have to choose: Staying low profile and keep the floating cities, or go all in and terraform the entire rock). Venus probably is the better candidate for terraforming than Mars, because it is nearly as massive as Earth, has all the volatiles for effective terraformation and all the technologies, that are needed to terraform Mars, are working just as good for Venus. So, If I had to choose which planet to terraform in a millenia lasting project, I would choose Venus over Mars. But then again: When it comes to maximizing population, we would have to disassemble even Venus to do so. Unless there is another way... ... Starlifting the Sun. Every material the planets can provide us with, the sun has orders of magnitude more of. So, when we have a Dyson Swarm already around the sun, we could use it (with some modifications), to "starlift" the star. This basicly alters the temperature on the sun's surface to our desires, which would cause it to create a solar wind channeled through one of its poles (where a collection facitlity catches the materials and condenses them into planets or even smaller stars; although I don't see any benefit creating an energy wasting smaller star distilled out of the sun's material). All this sounds complicated, and it probably is, but it is a rather brute force method that utilizes basic (high-) technologies, that we allready possess. So it is possible - just a hell lot of an effort to do it. One benefit of extracting material out of the sun (apart of the raw materials, that is): The sun's lifetime would be dramatically increased. Up to trillions of years (depending on the amount of materials extracted. Theorietically, we could extract the Sun to death if we wanted to). The same techniques will be possible for the Gasplanets too - just smaller and therefore easier to apply. Another benefit is: Mastering this technique will allow us to even colonize systems that don't have any planets. We could "just" starlift all the materials out of the given star to make what we need to live there. So, when we talk "Terraforming", we really talk about a tiny fraction of the options that we have for colonizing space - and Terraforming really comes in last on the list of the most viable solutions to create new living spaces. That's why I'm mostly on the pessimistic side of the question if the terraformation of planets is a desirable colonization strategy at all. I don't say nobody would ever attempt it, but I'm saying it's the least effective method from the plethora of better strategies to choose from, and will probably the last choice for every single colonization effort for this exact reason. - Tristan